
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log (- 1.0 u0))) (+ (/ cos2phi (* alphax alphax)) (/ sin2phi (* alphay alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -logf((1.0f - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = -log((1.0e0 - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log(Float32(Float32(1.0) - u0))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(sin2phi / Float32(alphay * alphay)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = -log((single(1.0) - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay))); end
\begin{array}{l}
\\
\frac{-\log \left(1 - u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + \frac{sin2phi}{alphay \cdot alphay}}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log (- 1.0 u0))) (+ (/ cos2phi (* alphax alphax)) (/ sin2phi (* alphay alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -logf((1.0f - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = -log((1.0e0 - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log(Float32(Float32(1.0) - u0))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(sin2phi / Float32(alphay * alphay)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = -log((single(1.0) - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay))); end
\begin{array}{l}
\\
\frac{-\log \left(1 - u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + \frac{sin2phi}{alphay \cdot alphay}}
\end{array}
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (* (/ (log1p (- u0)) (fma (/ sin2phi alphay) alphax (/ cos2phi (/ alphax alphay)))) (* alphay (- alphax))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return (log1pf(-u0) / fmaf((sin2phi / alphay), alphax, (cos2phi / (alphax / alphay)))) * (alphay * -alphax);
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(log1p(Float32(-u0)) / fma(Float32(sin2phi / alphay), alphax, Float32(cos2phi / Float32(alphax / alphay)))) * Float32(alphay * Float32(-alphax))) end
\begin{array}{l}
\\
\frac{\mathsf{log1p}\left(-u0\right)}{\mathsf{fma}\left(\frac{sin2phi}{alphay}, alphax, \frac{cos2phi}{\frac{alphax}{alphay}}\right)} \cdot \left(alphay \cdot \left(-alphax\right)\right)
\end{array}
Initial program 59.1%
sub-neg59.1%
log1p-def98.3%
Simplified98.3%
associate-/r*98.4%
associate-/r*98.4%
frac-add98.2%
Applied egg-rr98.2%
*-commutative98.2%
*-commutative98.2%
+-commutative98.2%
fma-def98.2%
*-commutative98.2%
associate-*l/98.1%
Simplified98.1%
associate-/r/98.6%
associate-/l*98.7%
*-commutative98.7%
Applied egg-rr98.7%
Final simplification98.7%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log1p (- u0))) (+ (/ cos2phi (* alphax alphax)) (* sin2phi (pow alphay -2.0)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / ((cos2phi / (alphax * alphax)) + (sin2phi * powf(alphay, -2.0f)));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(sin2phi * (alphay ^ Float32(-2.0))))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + sin2phi \cdot {alphay}^{-2}}
\end{array}
Initial program 59.1%
sqr-neg59.1%
sub-neg59.1%
log1p-def98.3%
sqr-neg98.3%
associate-/r*98.4%
Simplified98.4%
associate-/r*98.3%
clear-num98.4%
associate-/r/98.3%
pow298.3%
pow-flip98.5%
metadata-eval98.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (alphax alphay u0 cos2phi sin2phi)
:precision binary32
(let* ((t_0 (* (/ sin2phi alphay) alphax)))
(if (<= sin2phi 4.999999980020986e-12)
(/ (* alphax (* u0 alphay)) (+ t_0 (/ alphay (/ alphax cos2phi))))
(/ (- (log1p (- u0))) (/ t_0 (* alphay alphax))))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
float t_0 = (sin2phi / alphay) * alphax;
float tmp;
if (sin2phi <= 4.999999980020986e-12f) {
tmp = (alphax * (u0 * alphay)) / (t_0 + (alphay / (alphax / cos2phi)));
} else {
tmp = -log1pf(-u0) / (t_0 / (alphay * alphax));
}
return tmp;
}
function code(alphax, alphay, u0, cos2phi, sin2phi) t_0 = Float32(Float32(sin2phi / alphay) * alphax) tmp = Float32(0.0) if (sin2phi <= Float32(4.999999980020986e-12)) tmp = Float32(Float32(alphax * Float32(u0 * alphay)) / Float32(t_0 + Float32(alphay / Float32(alphax / cos2phi)))); else tmp = Float32(Float32(-log1p(Float32(-u0))) / Float32(t_0 / Float32(alphay * alphax))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{sin2phi}{alphay} \cdot alphax\\
\mathbf{if}\;sin2phi \leq 4.999999980020986 \cdot 10^{-12}:\\
\;\;\;\;\frac{alphax \cdot \left(u0 \cdot alphay\right)}{t_0 + \frac{alphay}{\frac{alphax}{cos2phi}}}\\
\mathbf{else}:\\
\;\;\;\;\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{t_0}{alphay \cdot alphax}}\\
\end{array}
\end{array}
if sin2phi < 4.99999998e-12Initial program 50.3%
sub-neg50.3%
log1p-def98.4%
Simplified98.4%
associate-/r*98.6%
associate-/r*98.6%
frac-add98.4%
Applied egg-rr98.4%
*-commutative98.4%
*-commutative98.4%
+-commutative98.4%
fma-def98.5%
*-commutative98.5%
associate-*l/98.2%
Simplified98.2%
Taylor expanded in u0 around 0 76.7%
*-commutative76.7%
associate-*l/76.7%
*-commutative76.7%
associate-/l*77.0%
Simplified77.0%
if 4.99999998e-12 < sin2phi Initial program 63.2%
sub-neg63.2%
log1p-def98.3%
Simplified98.3%
associate-/r*98.3%
associate-/r*98.3%
frac-add98.0%
Applied egg-rr98.0%
*-commutative98.0%
*-commutative98.0%
+-commutative98.0%
fma-def98.0%
*-commutative98.0%
associate-*l/98.0%
Simplified98.0%
Taylor expanded in sin2phi around inf 95.5%
*-commutative95.5%
associate-*l/95.6%
*-commutative95.6%
Simplified95.6%
Final simplification89.7%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log1p (- u0))) (+ (/ cos2phi (* alphax alphax)) (/ sin2phi (* alphay alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(sin2phi / Float32(alphay * alphay)))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + \frac{sin2phi}{alphay \cdot alphay}}
\end{array}
Initial program 59.1%
sub-neg59.1%
log1p-def98.3%
Simplified98.3%
Final simplification98.3%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log1p (- u0))) (+ (/ cos2phi (* alphax alphax)) (/ (/ sin2phi alphay) alphay))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) / alphay));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(sin2phi / alphay) / alphay))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + \frac{\frac{sin2phi}{alphay}}{alphay}}
\end{array}
Initial program 59.1%
sqr-neg59.1%
sub-neg59.1%
log1p-def98.3%
sqr-neg98.3%
associate-/r*98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (alphax alphay u0 cos2phi sin2phi)
:precision binary32
(if (<= sin2phi 4.999999980020986e-12)
(/
(* alphax (* u0 alphay))
(+ (* (/ sin2phi alphay) alphax) (/ alphay (/ alphax cos2phi))))
(/ (- (pow alphay 2.0)) (- (* sin2phi 0.5) (/ sin2phi u0)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
float tmp;
if (sin2phi <= 4.999999980020986e-12f) {
tmp = (alphax * (u0 * alphay)) / (((sin2phi / alphay) * alphax) + (alphay / (alphax / cos2phi)));
} else {
tmp = -powf(alphay, 2.0f) / ((sin2phi * 0.5f) - (sin2phi / u0));
}
return tmp;
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
real(4) :: tmp
if (sin2phi <= 4.999999980020986e-12) then
tmp = (alphax * (u0 * alphay)) / (((sin2phi / alphay) * alphax) + (alphay / (alphax / cos2phi)))
else
tmp = -(alphay ** 2.0e0) / ((sin2phi * 0.5e0) - (sin2phi / u0))
end if
code = tmp
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) tmp = Float32(0.0) if (sin2phi <= Float32(4.999999980020986e-12)) tmp = Float32(Float32(alphax * Float32(u0 * alphay)) / Float32(Float32(Float32(sin2phi / alphay) * alphax) + Float32(alphay / Float32(alphax / cos2phi)))); else tmp = Float32(Float32(-(alphay ^ Float32(2.0))) / Float32(Float32(sin2phi * Float32(0.5)) - Float32(sin2phi / u0))); end return tmp end
function tmp_2 = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = single(0.0); if (sin2phi <= single(4.999999980020986e-12)) tmp = (alphax * (u0 * alphay)) / (((sin2phi / alphay) * alphax) + (alphay / (alphax / cos2phi))); else tmp = -(alphay ^ single(2.0)) / ((sin2phi * single(0.5)) - (sin2phi / u0)); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;sin2phi \leq 4.999999980020986 \cdot 10^{-12}:\\
\;\;\;\;\frac{alphax \cdot \left(u0 \cdot alphay\right)}{\frac{sin2phi}{alphay} \cdot alphax + \frac{alphay}{\frac{alphax}{cos2phi}}}\\
\mathbf{else}:\\
\;\;\;\;\frac{-{alphay}^{2}}{sin2phi \cdot 0.5 - \frac{sin2phi}{u0}}\\
\end{array}
\end{array}
if sin2phi < 4.99999998e-12Initial program 50.3%
sub-neg50.3%
log1p-def98.4%
Simplified98.4%
associate-/r*98.6%
associate-/r*98.6%
frac-add98.4%
Applied egg-rr98.4%
*-commutative98.4%
*-commutative98.4%
+-commutative98.4%
fma-def98.5%
*-commutative98.5%
associate-*l/98.2%
Simplified98.2%
Taylor expanded in u0 around 0 76.7%
*-commutative76.7%
associate-*l/76.7%
*-commutative76.7%
associate-/l*77.0%
Simplified77.0%
if 4.99999998e-12 < sin2phi Initial program 63.2%
associate-/r*63.2%
Simplified63.2%
Taylor expanded in cos2phi around 0 62.4%
mul-1-neg62.4%
associate-/l*62.3%
distribute-neg-frac62.3%
sub-neg62.3%
mul-1-neg62.3%
log1p-def96.0%
mul-1-neg96.0%
Simplified96.0%
Taylor expanded in u0 around 0 87.9%
+-commutative87.9%
mul-1-neg87.9%
unsub-neg87.9%
*-commutative87.9%
Simplified87.9%
Final simplification84.5%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (* alphax (* u0 alphay)) (+ (* (/ sin2phi alphay) alphax) (/ alphay (/ alphax cos2phi)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return (alphax * (u0 * alphay)) / (((sin2phi / alphay) * alphax) + (alphay / (alphax / cos2phi)));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = (alphax * (u0 * alphay)) / (((sin2phi / alphay) * alphax) + (alphay / (alphax / cos2phi)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(alphax * Float32(u0 * alphay)) / Float32(Float32(Float32(sin2phi / alphay) * alphax) + Float32(alphay / Float32(alphax / cos2phi)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = (alphax * (u0 * alphay)) / (((sin2phi / alphay) * alphax) + (alphay / (alphax / cos2phi))); end
\begin{array}{l}
\\
\frac{alphax \cdot \left(u0 \cdot alphay\right)}{\frac{sin2phi}{alphay} \cdot alphax + \frac{alphay}{\frac{alphax}{cos2phi}}}
\end{array}
Initial program 59.1%
sub-neg59.1%
log1p-def98.3%
Simplified98.3%
associate-/r*98.4%
associate-/r*98.4%
frac-add98.2%
Applied egg-rr98.2%
*-commutative98.2%
*-commutative98.2%
+-commutative98.2%
fma-def98.2%
*-commutative98.2%
associate-*l/98.1%
Simplified98.1%
Taylor expanded in u0 around 0 76.8%
*-commutative76.8%
associate-*l/76.7%
*-commutative76.7%
associate-/l*76.8%
Simplified76.8%
Final simplification76.8%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ u0 (+ (/ cos2phi (* alphax alphax)) (/ (/ sin2phi alphay) alphay))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) / alphay));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) / alphay))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(u0 / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(sin2phi / alphay) / alphay))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) / alphay)); end
\begin{array}{l}
\\
\frac{u0}{\frac{cos2phi}{alphax \cdot alphax} + \frac{\frac{sin2phi}{alphay}}{alphay}}
\end{array}
Initial program 59.1%
associate-/r*59.1%
Simplified59.1%
Taylor expanded in u0 around 0 76.7%
mul-1-neg76.7%
Simplified76.7%
Final simplification76.7%
herbie shell --seed 2023312
(FPCore (alphax alphay u0 cos2phi sin2phi)
:name "Beckmann Distribution sample, tan2theta, alphax != alphay, u1 <= 0.5"
:precision binary32
:pre (and (and (and (and (and (<= 0.0001 alphax) (<= alphax 1.0)) (and (<= 0.0001 alphay) (<= alphay 1.0))) (and (<= 2.328306437e-10 u0) (<= u0 1.0))) (and (<= 0.0 cos2phi) (<= cos2phi 1.0))) (<= 0.0 sin2phi))
(/ (- (log (- 1.0 u0))) (+ (/ cos2phi (* alphax alphax)) (/ sin2phi (* alphay alphay)))))